In the games

Pokémon Black and White

The player must first go talk to Skyla at the top of the Celestial Tower and ring the tower's bell before she'll return to the Gym so it can be challenged.

The inside of the Gym is full of cannons which the player must use to make their way to Skyla. Most of these cannons help the player to progress to Skyla; however, some will blast the player back to a Trainer. The cannon behind Skyla works as a shortcut back to the entrance.

Pokémon Black 2 and White 2

The interior of the Gym has been redesigned to feature large fans at the back of the Gym that can blow the player across the room. Upon attempting to reach Skyla, the player can hide behind walls to avoid the heavy gusts of wind from the large fans. After defeating Skyla, a large fan that stands behind Skyla blows the player out of the Gym.

Items

In the anime

Mistralton Gym in the anime appears to be inspired by its game counterpart, though it does have a dirt battlefield. It has a cannon that shoots Skyla into the air that will explode into confetti when she makes her landing.

It first appeared in Cilan Takes Flight! when Ash and his friends first arrived in Mistralton City and found out that Skyla accepts challenges outside the gym that she plays out in her head, which she calls "Air Battles." Her grandfather, Miles explained that Skyla had lost her motivation as a Gym Leader, and no longer accepted battles from Trainers. Infuriated, Cilan challenged her to a battle, which she accepted, feeling a battle between Gym Leaders would be more exciting. Cilan ended up losing the battle, and Ash then challenged her, and insisted that she battled in a proper one-on-one battle. She reluctantly accepted, and in An Amazing Aerial Battle!, Ash managed to defeat her and earn himself the Jet Badge. Skyla then agreed to take part in battles instead of Air Battles from then on, much to Miles's relief.

Much like in the games, the Mistralton Gym has a cannon and hoops suspended mid-air, which Skyla was once seen using during her entrance.

Swanna is one of Skyla's three Pokémon. It was first used in a Gym Battle against Cilan. It struggled a bit battling Stunfisk which it had a type disadvantage with and was also burned by its Scald. However, thanks to its Aqua Ring, it was able to overcome its burn and defeated Stunfisk.

In the manga

In the Pokémon Adventures manga

Mistralton Gym in the Pokémon Adventures manga

The Mistralton Gym appeared in Up in the Air and The Battle Within, where Black battled Skyla in a Gym battle. After being pushed down from the Celestial Tower by Skyla and carried into the Gym by her Swanna, Black was fired around the Gym by its cannons before finally landing into the one near Skyla. During the battle, Skyla told Black she would blast him straight back to Nuvema Town if he lost. Luckily for Black, he won the battle, but Skyla departed to Nacrene City with the other Gym Leaders without handing him the Badge. However, the cannon Black was in then fired him out of the Gym and onto the top floor of Celestial Tower. After Black rung the bell at the top of the tower, Skyla sent her Swanna down to him to give him a Jet Badge as a proof of his victory.